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Neurone structure

Cells and control · Neurones and reflexes · note 2 of 5

Spec 2.13Download these notes (PDF)7 pages

Neurone structureSpec 2.13

Neurones are specialised to carry electrical impulses quickly over long distances.

Axon
A long fibre that carries electrical impulses away from the cell body.
Dendron
A fibre that carries electrical impulses towards the cell body.
Myelin sheath
A fatty layer around the neurone that insulates it and speeds up the transmission of impulses.
A motor neurone with dendrites, a cell body, a long axon covered in a myelin sheath and nerve endings on a muscle (the effector), and a sensory neurone with a long dendron from a receptor to its cell body, then a short axon to its nerve endings; arrows show the direction of the impulse.Tap to enlarge
A motor neurone and a sensory neurone. The myelin sheath insulates the fibre and speeds up impulses.